Spring



Feb. 23, 1965 SVOREN ETAL 3,170,447

SPRING Filed June 14, 1963 II 1 I I r INVENTORvS'. Jae/rs L7. 6 rare 77 United States Patent 3,170,447 SPRING Louis J. Svoren and Eugene C. Van Eimeren, in, Racine, Wis asignors to Walker Manufacturing Company, a corporation of Delaware Filed June 14, 1963, Ser. No. 288,040 13 Claims. (Cl. 123-119) This invention relates to crankcase ventilation systems and more particularly to a flame stop therefor.

In crankcase ventilating systems, it is customary to provide flame stop means in the blowby passage'connecting the crankcase with the combustion air intake system. Some of the disadvantages of prior art flame stops have been high cost, difficulty of assembly within a blowby passage, inability to stop fiamepropagationthrough a blowby passage while at the same time permitting adequate flow of blowby from the crankcase to the air intake system, and clogging and deterioration in use.

Accordingly, an object of the present invention is to provide a low cost flame stop which is capable of dispersing a flame pattern and quenching the flame while at the same time allowing necessary blowby flow through the passage in which it ismounted.

Another object of the :present invention is to provide a new and improved flame stop, for a crankcase ventilating system which is far less susceptible to clogging and deterioration in use than previous flame stops.

Other objects and advantages of the present invention will be apparent to those skilled in the art to which this invention relates by reference to the following detailed description and the accompanying drawing wherein:

FIGURE 1 is a side elevational view partly in section of a crankcase ventilating system apparatus incorporating the inventive principles; a

I FIGURE 2 isan enlarged sectional view of the flame stop poxtion ofv the apparatus shownin FIGURE 1; and

FIGURE 3 is an enlarged side elevational view of the flame stop.

Referring. now' to FIG. 1, the crankcase ventilating system in which the present invention is illustratively incorporatedincludes an engine having a crankcase 12, an oil filler tube 14 and an oil filler tube cap 16. A filter 18 and a valve 20 are provided in the'filler tube cap to enable air to be drawn into the crankcase. The engine is further provided with an intake manifold '22, a carburetion unit 24 having a throttle valve 26, andan air cleaner unit 28 havinga suitable filter element 30 and a combustion air intake 32. A length of hose 32, or the like, is connected at one end 34 to the crankcase 12 and at the other end 35 to the air cleaner 28 to establish a flow of blowby gases from the crankcase to the air cleaner. A branch hose 36 may be provided and is connected to the hose 32 at one end 38 and is connected to the intake passage 22 below the throttle valve 26 at the other end 40. Av combination control orifice and cleaner 42 is mounted at the juncture of the branch passage provided by hose 36 and the main passage provided by hose 32. In order to stop flame travel through the passage 32, a

. flame stop means 50 is, in the preferred embodiment,

mounted in the upper end of the passage 32.

Referring now to FIG. 2, the flame stop means 50 is shown to comprise a coiled wire spring element having two substantially conically shaped portions 52, 54 which extend toward one another and terminate in a central portion 56 defining a small aperture therebetween. Opposite ends of the elements are substantially flat and provide enlarged base portions 58, 60. It may be noted that the flame stop has substantially an hour glass configuration. Each of the coils of the wire are preferably spaced from one another a distance approximately egg to A of an inch.

3,170,447 Patented Feb. 23, 1965 The inside diameter of the aperture at the portion 56 should, preferably, not exceed .090 inch. A suitable embodiment of the flame stop may be made from .035 diameter wire having a'total axial length of approximately 1%; inches, and a maximum diameter of approximately .760 inch. Each section of conical coils may include eight full coils. Furthermore, the diameter of the base portion 58 may be made slightly smaller than the diameter of the base portion 60 with the difference in diameters in the preferred embodiment being approximately .100 inch.

The wire itself may be characterized as hard drawn spring wire. a

The'hose 32 is connected to the combustion air intake systemthrough a suitable aperture 70 provided in a side wall of the air cleaner casing 28 and is secured therein by a fitting 72 which comprises a sleeve having a plurality' of radially outwardly extending ribs 74 formed about its outer periphery and adapted to seat the adjacent edge of the air cleaner casing as indicated. A shoulder 76 is formed in the sleeve at one end and a radially inwardly extending annular rib 78 may be formed in the other end of thesleeve. The end of the hose 32 is secured in place within the sleeve by inward distortion of a portion 80 of the hose in alignment with the rib 78. Other suitable clamping means may be utilized.

The flame stop is adapted to be mounted between the shoulder 76 and a shoulder 82 formed by the edge of the rib 78 and the deflected portion 80 of the hose end. As shown in FIG. 2, the spring is seated between the two shoulders in'a' slight state of compression with adjacent coils spaced from one another to permit flow of blowby while preventing propagation of a flame.

In operation, with a flame wave traveling in the direc, tion of the arrow 84 toward the crankcase 12, the first portion 54 of the flame stop tends to break up and disburse the flame pattern radially outwardly. The cavity 86 defined betweenthe surrounding sleeve, the end of the hose 32, and the outerperipheral surfaces of the flame stop servesv to quench the flame as it passes through and among the coils of the spring. The second conical portion 58. completes the flame quenching process and prevents any flame from traveling through into the tube 32. The diameter of the passage in the central portion 56 is sufficiently small to prevent passage of flame therethrough.

It will be readily appreciated that almaximum amount of I aeration is vprovirledlin the spring consistent with the requirements of flame stoppage. In other words, at all times blowby is able to travelrelatively freely through the flame stop because of the central passage in the area 56 and because of the relatively wide spacing between adjacent coils of the flame stop. The relative wide spacing of the flame stop and the relatively large diameter of the central hole prevents clogging and greatly reduces the tendency for the flame stop to eventually close due to contamination by the blowby gases carried through the tube passage.

Since the inventive principles may be otherwise variously embodied in alternative ventilating systems by various modifications, it is intended that the scope of the appended claims be construed to include alternative embodiments which incorporate the inventive principles.

What is claimed is:

1. In a flame stop for a crankcase ventilating system having a blowby flow passage connected to the crankcase, the improvement comprising a flame stop formed from a continuous section of coiled wire having a plurality of spaced coils and being mounted within said passage, the coils of said wire having a spacing forming a restriction in said passage suflicient to prevent the propagation of flame through the passage to the crankcase while also 3 having a spacing permitting flow of blowby through the passage from the crankcase...

2. In a flame stop for a crankcase ventilating system, the improvement comprising a plurality of coils of wire,

said coils having varying diameters and tapering from a maximum diameter approximately equal to the crankcase ventilating passage in which the flame stop is to be inserted to a minimum diameter approximately equal to the largest passage through which flame propagation will be prevented.

3. The invention as defined in c1aim,2 and wherein said coils of wire are spaced from one another a substantial distance to permit substantially unimpeded flow of blowby therethrough.

4. The invention as defined in claim 2 and wherein said central passage has a diameter of approximately .090 inch.

5 The invention as defined in claim 2 and wherein the spacing of. said coils from one another is approximately .032 inch.

6. In a flame stop for a crankcase ventilating system, or the like, the improvement comprising a first portion of coiled wire, a second portion of coiled wire, said portions of coiled wire tapering toward one another and defining a flame quenching space therebetween.

7. In a crankcase ventilating system, a blowby passage extending from the engine crankcase to the air intake systern, a pair of spaced shoulders formed in said passage, a

flame stop in the form a continuous helical coil of wire extending axially in said passage between said shoulders, and inner and outer concentric passage means provided in said passage by said wire.

8. The invention as defined in claim 7 and wherein said continuous helical. coil of wire comprises a plurality of coiled turns spaced from one another and having varying diameters.

9. The invention as defined inclaim 7 and wherein said continuous helical coil of wire comprises a first portion of coiled turns, said first portion of coiled turns tapering progressively from a maximum diameter to a minimum diameter, and a second portion of coiled turns, said second portion of coiled turns tapering progressivelyfrom a maximum diameter to a minimum diameter, and said first portion and said second portion of coiled turns being connected centrally to one another to define an hour glass flame stop configuration.

i 10. In a flame stop for a crankcase ventilating system, the improvement comprising a wire formed into a plurality of coils, said coils being spaced from one another and progressively changing dimensions from opposite end portions of substantially equal diameter to a. central portion therebetween of reduced diameter.

11. In a crankcase ventilating system for an engine having a blowby passage extending from the engine crankcase to the air intake system of the engine, the invention comprising; a flame stop mounted in said passage, said flame stop being elongated and extending a substantial axial length, said flame stop defining a plurality of co- 12. In a crankcase ventilating system for an engine.

having a blowby passage extending from the engine crankcase to the air intake system of the engine, the invention comprising a flexible tube of resilient material defining a I part of said passage, an elongated coil of wire mounted V in said passage to form a flame stop, a central passage formed by said wire and defined by the inner peripheral surfaces thereof, and portions of said elongated coil of wire having an outer peripheral dimension larger than an inside dimension of said passage and being held within said passage in intimate surface to surface engagement therewith.

13. In a crankcase ventilating system for an engine having a passage extending between the engine crankcase and the engine air intake system, said passageway having axially spaced inlet and outlet openings, a portion of the passage being peripherally continuous along a substantial axial distance, the invention comprising a length of wire wound into axially extending helical coils to form a flame stop, said flame stop being mounted in said. portion of the passage, an outer peripheral portion of the flame stop being in surface to surface engagement with an inner peripheral portion of the passage, another outer peripheral portion of said flame stop being located in radially inwardly spaced relationship to the inner peripheral portion of the passage and defining flow passage-means of reduced size relative to said passage, and restricted flow passage means provided between adjacent coils of said flame stop suflicient to prevent the propagation of flame through said passage.

References Cited by the Examiner UNITED STATES PATENTS 954,944 5/ 10 Steward 48-192 1,800,977 4/31 Anschicks 48-192 2,686,504 8/54 Hill 123-119 2,906,252 9/59 Beardsley 123-119 3,030,942 4/62 Thompson 123-119 RICHARD a. wrLKrNsoN, Primary Examiner.

KARL J. ALBRECHT, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE ()F' L-CORRE'CTION Patent No. 3,170,447 I I FebruaryMZS, 1965 Louis J. Svoren et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 46, for "954,944" read 958,944

Signed and sealed this 17th day of August 1965.

(SEAL) Attest:

ERNEST w. SWIDER EDWARD J. BRENNER AIM-sting Officer Commissioner of Patents UNITED STATES-PATENT OFFICE CERTIFICATE :QFzCORBE'CTION Patent No. 3,170,447 FebruaryZS, 1965 Louis J. Svoren et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 46, for "954,944" read 958,944

Signed and sealed this 17th day of August 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J'. BRENNER Attcsting Officer Commissioner of Patents 

1. IN A FLAME STOP FOR A CRANKCASE VENTILATING SYSTEM HAVING A BLOWBY FLOW PASSAGE CONNECTED TO THE CRANKCASE, THE IMPROVEMENT COMPRISING A FLAME STOP FORMED FROM A CONTINUOUS SECTION OF COILED WIRE HAVING A PLURALITY OF SPACED COILS AND BEING MOUNTED WITHIN SAID PASSAGE, THE COILS OF SAID WIRE HAVING A SPACING FORMING A RESTRICTION IN SAID PASSAGE SUFFICIENT TO PREVENT THE PROPAGATION OF FLAME THROUGH THE PASSAGE TO THE CRANKCASE WHILE ALSO HAVING A SPACING PERMITTING FLOW OF BLOWBY THROUGH THE PASSAGE FROM THE CRANKCASE. 